Torture and game theory

The latest issue of Political Research Quarterly has an interesting and important exchange about the use of game theory to understand the effectiveness of torture for eliciting truthful information. In this post I summarize the discussion, which is quite instructive for illustrating the prejudices and misunderstandings people have about the role and utility of game theory as a tool to gain insights into the social world.

In the original article, Schiemann builds a strategic incomplete-information game between a detainee (who can either posses valuable information or not, and be either ‘strong’ or ‘weak’) and a state which can be either ‘pragmatic’ (using torture only for valuable information) or ‘sadistic’ (torturing in all circumstances). There are two additional parameters capturing uncertainty about the value and completeness of the information provided by the detainee, and two styles of interrogation (providing leading evidence or not). The article then proceeds to identify the equilibria of the game, which turn out to be quite a few (six), and quite different – in some, truthful information is provided while in others, not; in some, torture is applied while in others, not; etc…. At this point you will be excused for wondering what’s the point of the formal modeling if it only shows that, depending on the parameters, different things are possible.

Schiemann, however, makes a brilliant move by comparing each of these equilibria to some minimal normative standards that proponents of torture claim to uphold – namely, that torture should not be used on detainees who have provided all their information, that transmitted information should be generally reliable, and that in all cases only the minimum effective amount of torture should be applied. It turns out that none of these minimal normative standards are sustained by any of the equlibria of the game. If interrogational torture is to ‘generate valuable information, innocent detainees must be tortured for telling the truth’. The intuition is that unless the threat of torture is present, even ‘weak’ detainees would not confess, but for the threat of the torture is to be credible, it needs to be applied to innocent detainees as well (which, of course, from the point of view of the state are observationally equivalent to strong and knowledgeable detainees). Things get even uglier. ‘Proposition 4. Once torture is admitted as an interrogation technique, the strategic incentives facing the interrogator result in increasingly harsh forms of torture.’ Overall, the conclusion is that, ‘An outcome resulting in valuable information…is possible, but the conditions supporting it are empirically unlikely.’

Let’s recap what Schiemann’s formal analysis has demonstrated: the use of torture can never extract valuable information unless innocents are tortured and the frequency and intensity is rather high, and even then it would be very difficult to separate valid information from all the other ‘confessions’ made during the interrogations. For me, this is a devastating critique on the use of torture – the analysis not only shows that the effectiveness of torture is likely to be very low (empirical evidence has already pointed in that direction), but it shows why torture doesn’t work (unless one violates minimal normative standards that even proponents of the practice espouse).

Dustin Ells Howes, however, begs to differ. In a response to this analysis, entitled ‘Torture Is Not a Game: On the Limitations and Dangers of Rational Choice Methods‘, he questions the fundamental premise of the analysis that torture can be modeled as a strategic interaction between agents who possess information, preferences and control over their actions. His main point is that under torture humans cannot be considered to have any agency at all. Fair enough, but then he proceeds to discuss how some individual can withstand torture after all by the force of ‘free will’. So, ultimately there are distinct states of the world that follow the exercise of torture – ‘confession’ (false or real) and ‘no confession’. So what’s the quibble with the game-theoretic analysis? Granted, it sound a bit perverse to talk about confessing under circumstances that destroy your entire sense of being a person, in addition to overwhelming physical pain that they bring, as a choice, but it matters little for the analysis whether you label it ‘choice’ or something else (‘expression of a strong free will'[?]). The fact remains that the state cannot sort out in advance which detainees possess information, which will confess, and which have already told everything they know. So torturing often and harshly and punishing innocents and those who actually reveal everything they know is unavoidable once one accepts the use of torture as a legitimate tool.

But in the mind of Howes, one should not even try to reason about the effectiveness of torture. It is dangerous to attempt to model torture, because, even if the current model shows that torture is ineffective and unjustifiable, once the principle of reasoning on the basis of formal models is accepted, others will build models that might show that torture works.

‘..[B]y placing his model within the framework of social science, he invites others to challenge him on that basis. If creating a formal model of interrogational torture is a legitimate way to argue against it, then social scientists could legitimately use the same methods to argue for it.’

At one level, I agree. Decades of game-theoretic modeling in economics have shown that by choosing the right assumptions and setup of the game, one can derive any result one wishes. But at the same time, there is something characteristically medieval about the argument – torture should be beyond the realm of reason, the only arguments we should have about the practice should be emotional and moral, not rational and theoretical. Was it Anselm of Canterbury who lamented himself for being able to prove the existence of God, anticipating that reason would be ultimately used to deny God’s presence?

What’s more annoying about Howes’ critique is that instead of discussing the original analysis, he prefers to attack rational choice in general as a research paradigm: ‘Themost strident critics of rational choice theory argue that it distorts reality in a way that is corrosive to democracy.’…‘The close relationship between the rise of rational choice theory in the social sciences and U.S.government and military initiatives is well established.‘ This makes as much sense as rejecting the physics of nuclear fusion because its study has its origins in Nazi Germany. From these blanket statements about rational choice, Howe’s jups to the conclusion that ‘Schiemann’s formal model is conducive to bureaucratic violence.’ Not sure what that means but it sounds nasty.

Predictably, Schiemann’s response easily demolishes these ‘critiques’ and reaffirms the utility of game theory to shed light on normative political questions. But I find it a bit disturbing that crutiques of the use of reason (and models) to shed light on social and political phenomena can still find a place on the pages of scientific journals at all.

P.S. Exchanges on the pages of academic journals are a great way to learn. Here is another post which reviews an exchange related to gender discrimination at work.